For what it is worth, I offer you 'Rollings Law of
Price and Performance'. 'For a given state of the
art, performance increases with the square root of
wingspan; price increases with the square of wing span.'

At 07:36 12 November 2004, Bruce Hoult wrote:
In article ,
(Erik mann) wrote:
Or, maybe the design goal should be 40:1 performance
at the lowest cost,
irrespective of span?

40:1 isn't actually what people want, otherwise the
Phoebus would be a
lot more popular than it is.

What is the reason for more span? It decreases induced
drag at high
angles of attack. So less span is worse because it
means you won't be
able to thermal slowly and efficiently, right? Just
like the PW-5.
Well, no, the PW5 thermals beautifully. The problem
with it is that it
needs very thick wings to do that, and this actually
penalises it at
*high* speed, not low speed. A glider similar to the
PW-5 could easily
have thinner wings, a better best L/D and *much* better
high speed
performance. It just wouldn't be able to fly as slowly
for thermalling
and -- perhaps more importantly for low time pilots
-- for landing.

--
Bruce | 41.1670S | \ spoken | -+-
Hoult | 174.8263E | /\ here. | ----------O----------